Arm, the chip designer, has long been the subject of takeover talk, and has long dismissed the idea. But its shares have jumped to the top of the FTSE 100 today after comments from a US group about possible acquisitions.

Normally Intel or Apple are mentioned as possible predators for Arm, but this time the name in the frame is software giant Oracle. And what seems to have prompted the interest is a comment from Oracle's chief executive Larry Ellison that he wanted to boost the company's technology by buying suitable businesses, and a microchip company could fit the bill.

So UK investors immediately latched onto Arm as a possible target, and its shares are up 19.4p at 410.2p, valuing the business at £5.4bn. The company's shares have more than doubled this year on takeover speculation, and clearly it is not going to go away.